The present invention relates to milling cutters and especially to insert-carrying cartridges usable in milling cutters.
Milling cutters are known which comprise a milling body that is rotatable about an axis and carries a plurality of cutting inserts disposed in circumferentially spaced relationship around an outer periphery of the milling body.
It has been proposed to mount the inserts on holders and secure the holders in place by wedges which are attached to the milling body by screws. However, the wedges tend to become tightly secured and difficult to remove. Also, the pockets formed in the milling body to receive the holders must be enlarged to also receive the wedges. That can reduce the number of inserts that can be mounted on the milling body, as well as weaken the milling body (due to the removal of a greater amount of material to form the pockets).
It has been known to mount cutting inserts in a rotary body by means of self-contained cartridges, i.e, cartridges which carry their own securing mechanism. For example, see U.S. Pat. No. 650,013 and U.S. Pat. No. 4,097,174, each of which discloses a cartridge having an insert seat at the top end thereof and a center slot extending into the bottom and thereof. The slot divides the cartridge into a rigid cutting part and a pair of legs that can be elastically spread apart relative to the cutting part about respective fulcrums by a spreading screw threadedly attached within a hole that extends perpendicularly through the slot. By thus spreading apart the legs, the bottom ends of the legs can be brought into tight contact with respective walls of the cartridge-receiving pocket to frictionally retain the cartridge within the pocket. A shortcoming of that arrangement involves the fact that the engagement between the cartridge and the pocket occurs at essentially two points at the bottom of the cartridge (defined by the legs), leaving the cutting part unsupported and capable of “play”, i.e., of moving by an amount equal to the allowable manufacturing tolerances between the cartridge and the pocket. That results in chatter and poor tool life.
Also, the cartridges disclosed in U.S. Pat. Nos. 650,013 and 4,097,174 do not enable the cartridges to be adjusted to change the cutting depth.
Accordingly, it would be desirable to provide an improved insert cartridge.
It would also be desirable to provide such a cartridge which is simple to operate and does not cause the cartridge to be shifted during securement within a pocket.
It would be further desirable to provide such a cartridge which can be easily adjusted.
It would also be desirable to provide a cartridge which is less likely to produce chattering, and which exhibits longer cutter life.